CFT Series
Recirculating Chiller
NESLAB Manual P/N 002167
Rev. 08/20/97
Instruction and Operation Manual
NESLAB online
Product Service Information, Electronic Catalog,
Applications Notes, MSDS Forms, e-mail.
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CFT Series Recirculating Chiller
PREFACE
Compliance ............................................................................................ 3
Unpacking .............................................................................................. 3
Warranty ................................................................................................ 3
After-sale Support .................................................................................. 3
SECTION I
Safety
Warnings ............................................................................................... 4
Additional Warnings............................................................................... 5
SECTION II
General Information
Description ............................................................................................. 6
Specifications ........................................................................................ 6
Cooling Capacity.................................................................................... 8
Pump Capacity ...................................................................................... 8
SECTION III
Installation
Site ........................................................................................................ 9
Electrical Requirements ......................................................................... 10
Plumbing Requirements ........................................................................ 10
Fluids ..................................................................................................... 11
Water Quality Standards and Recommendations.................................. 12
Filling Requirements .............................................................................. 14
SECTION IV
Operation
Start Up.................................................................................................. 15
Analog Temperature Controller ............................................................. 15
Digital Temperature Controller .............................................................. 16
Pressure Relief Valve ............................................................................ 16
High Temperature Cutout (Optional) ..................................................... 17
CFT-300 High/Low Pressure Cutouts .................................................... 17
CFT-150 High Pressure Cutout ............................................................. 17
Heater Package (Optional) .................................................................... 18
External Pressure Regulator (Optional) ................................................. 19
SECTION V
Maintenance & Service
Service Contracts .................................................................................. 20
Draining the Reservoir ........................................................................... 20
Cleaning ................................................................................................. 20
Algae ...................................................................................................... 21
Pump Strainer ........................................................................................ 21
Pump Lubrication ................................................................................... 22
Hoses ..................................................................................................... 22
Suction Discharge Presssure/Speed Check .......................................... 22
SECTION VI
Troubleshooting
Checklist ................................................................................................ 23
Service Assistance ................................................................................ 23
Pump Flow Diagram .............................................................................. 24
WARRANTY
-1-
CFT Series Quick Reference Operating Procedures
Installation
The unit has an air-cooled refrigeration system.
Air is drawn in the front of the unit and discharged
through rear and side. Position the unit so the
intake and discharge are not impeded. Inadequate
ventilation will cause a reduction in cooling
capacity and, in extreme cases, compressor
failure.
When the unit is shut off, wait approximately five
minutes before restarting. This allows time for the
refrigeration pressures to equalize. If the pressuresare not allowed to equalize, the compressor
will short-cycle and no cooling will occur.
Analog Controller Temperature Adjustment
To adjust the temperature setpoint, turn the °C
dial on the front of the unit to the desired temperature.
Excessively dusty areas should be avoided and a
periodic cleaning schedule should be instituted.
For proper operation, the unit needs to pull
substantial amounts of air through a condenser. A
build up of dust or debris on the fins of the condenser will lead to a loss of cooling capacity.
Digital Controller Temperature Adjustment
To display the temperature setpoint, press and
hold the DISPLAY switch. To adjust the temperature setpoint, press and hold the DISPLAY switch
and turn the ADJUST knob until the desired
temperature setpoint is indicated on the digital
display. Once the setpoint is adjusted, release the
DISPLAY switch. The display will now indicate the
temperature of the fluid in the reservoir.
The unit will retain its full rated capacity in ambient temperatures up to approximately +24°C.
Make sure the voltage of the power source meets
the specified voltage, ±10%.
The plumbing connections are located on the rear
of the unit and are labelled either SUPPLY and
RETURN or OUTLET and INLET. These connections are ½ inch FPT, ¾ inch FPT for CFT-300s.
Remove the plastic protective plugs from both
plumbing connections. Connect the OUTLET/
SUPPLY fitting to the inlet of the instrument being
cooled. Connect the INLET/RETURN fitting to the
outlet of the instrument being cooled.
Periodic Maintenance
Periodically inspect the reservoir fluid. If cleaning
is necessary, flush the reservoir with a cleaning
fluid compatible with the circulating system and
the cooling fluid.
The cooling fluid should be replaced periodically.
When operating at low temperatures, the concentration of water in the cooling fluid will increase
over time, leading to a loss of cooling capacity.
To fill the reservoir remove the reservoir access
panel by unscrewing the thumbscrews. Locate the
reservoir plug (square nut). Remove the plug and
fill the reservoir with clean cooling fluid.
Before changing the cooling fluid, raise the unit's
operating temperature to de-ice the cooling coils.
Periodic vacuuming of the condenser fins is
necessary. The frequency of cleaning depends on
the operating environment. We recommend a
visual inspection of the condenser be made
monthly after initial installation. After several
months, the cleaning frequency will be established.
Tap water is the recommended fluid for operation
from +8°C to +30°C. Below +8°C, a non-freezing
fluid must be used. A mixture of tap water and
laboratory grade ethylene glycol is suggested.
Operation
Before starting the unit, double check all electrical
and plumbing connections. Make sure the circulating system has been filled with cooling fluid.
Units with PD pumps have a strainer. If debris is
in the system, the strainer will prevent the material
from being drawn into the pump and damaging the
pump vanes.
To start the unit, place the Power Switch to the on
position. The Power Switch illuminates (except for
the CFT-150) to indicate the system is operating.
To turn the unit off, place the Power Switch to the
off position.
After initial installation, the strainer may become
clogged. The strainer must be cleaned after the
first week of installation. After this first cleaning, a
monthly visual inspection is recommended. After
several months, the frequency of cleaning will be
established. Before cleaning, disconnect the
power cord from the power source and drain the
reservoir.
The Cool LED indicates the status of the refrigeration system. It illuminates to indicate the refrigeration system is removing heat from the cooling
fluid. As the operating temperature approaches
the setpoint, the LED will extinguish.
-2-
Preface
Compliance
Products tested and found to be in compliance with the requirements defined
in the EMC standards defined by 89/336/EEC as well as Low Voltage
Directive (LVD) 73/23/EEC can be identified by the CE label on the rear of
the unit. The testing has demonstrated compliance with the following directives:
LVD, 73/23/EEC
Complies with UL 3101-1:93
EMC, 89/336/EEC
EN 55011, Class A Verification
EN 50082-1:1992
IEC 1000-4-2:1995
IEC 1000-4-3:1994
IEC 1000-4-4:1995
For any additional information refer to the Letter of Compliance that shipped
with the unit (Declaration of Conformity).
Unpacking
Retain all cartons and packing material until the unit is operated and found
to be in good condition. If the unit shows external or internal damage, or
does not operate properly, contact the transportation company and file a
damage claim. Under ICC regulations, this is your responsibility.
If this product has been modified to operate at 0°C or lower, it has been
tested with a non-freezing fluid. Although the system has been drained,
some residual fluid may remain. This will not hinder your unit's performance.
Warranty
Units have a warranty against defective parts and workmanship for one full
year from date of shipment. See back page for more details.
After-sale Support
NESLAB is committed to customer service both during and after the sale. If
you have questions concerning the unit operation, contact our Sales Department. If your unit fails to operate properly, or if you have questions concerning spare parts or Service Contracts, contact our Service Department.
Before calling, please refer to the labels on the rear of the unit to obtain the
following information:
- unit BOM number ________________________________
- unit serial number ________________________________
- pump type ______________________________________
-3-
Section I Safety
Warnings
Warnings are posted throughout the manual. These warnings are designated by an exclamation mark inside an equilateral triangle and text
highlighted in bold. Read and follow these important instructions. Failure to
observe these instructions can result in permanent damage to the unit,
significant property damage, or personal injury or death.
Make sure you read and understand all instructions and safety precautions
listed in this manual before installing or operating your unit. If you have any
questions concerning the operation of your unit or the information in this
manual, please contact our Sales Department (see After-sale Support).
Never place the unit in a location where excessive heat, moisture, or
corrosive materials are present.
The unit construction provides extra protection against the risk of
electrical shock by grounding appropriate metal parts. The extra
protection may not function unless the power cord is connected to a
properly grounded outlet. It is the user's responsibility to assure a
proper ground connection is provided.
Never connect the OUTLET/SUPPLY or INLET/RETURN fitting to your
building water supply or any water pressure source.
Never use flammable or corrosive fluids with this unit. Distilled and
deionized water may be aggressive and cause material corrosion.
Please contact NESLAB before subjecting this unit to prolonged
exposure to distilled or deionized water.
Do not use automobile anti-freeze. Commercial anti-freeze contains
silicates that can damage the pump seals. Use of automobile antifreeze will void the manufacturer’s warranty.
Do not replace reservoir plug with a non-vented type or damage to
the tank may occur.
For personal safety and equipment reliability, the following procedure
should only be performed by a competent technician. Contact our
Service Department for assistance (see Preface, After-sale Support).
-4-
Additional Warnings
In addition to the specific warnings listed on the previous page the following
general warnings apply to you unit:
Performance of installation, operation, or maintenance procedures
other than those described in this manual may result in a hazardous
situation and may void the manufacturer's warranty.
Transport the unit with care. Sudden jolts or drops can damage the
refrigeration lines.
Observe all warning labels.
Never remove warning labels.
Never operate damaged or leaking equipment.
Never operate the unit without cooling fluid in the reservoir.
Always turn off the unit and disconnect the power cord from the power
source before performing any service or maintenance procedures, or
before moving the unit.
Always empty the reservoir before moving the unit.
Never operate equipment with damaged power cords.
Refer service and repairs to a qualified technician.
-5-
Section II General Information
Description
The CFT Recirculating Chiller is designed to provide a continuous supply of
cooling fluid at a constant temperature and volume.
The unit consists of an air-cooled refrigeration system, a sealable reservoir,
recirculating pump, and a temperature controller.
Throughout the manual, you will be asked to consult the unit’s serial number
label or the pump identification label for specific information. Both labels are
located on the rear of the unit.
Specifications
CFT-25
CFT-33
CFT-75
CFT-150
CFT-300
580 Watts
475 Watts
950 Watts
1000 Watts
2100 Watts
1900 Watts
4500Watts
3735 Watts
10650 Watts
9000 Watts
1
Cooling Capacity
60Hz
50Hz
+5°C to +30°C
Temperature Range
Temperature Stability2,3
Analog Temperature
Controller
Digital Temperature
Controller
+5°C to +35°C
±1.0°C
±0.5°
Reservoir Volume
Gallons
Liters
0.5
1.9
1.1
4.1
R134a
Refrigerant
1.
2.
3.
±1.0°
1.8
6.8
5.6
21.3
R22
Circulating water at 20°C, at 20°C ambient. Cooling capacity will vary depending on fluid
temperature, ambient temperature, and cooling fluid. A PD-1 pump was used in the CFT-25, a
PD-2 in the other units.
Stability determined for CFT-150 analog unit with 75% heat load @ 20°C circulating temperature.
CFT-300 stabliity determined with 86% heat load.
-6-
B
H
C
A
G
F
E
D
CFT25
CFT33
CFT75
CFT150
CFT300
22
24½
26½
36¾
43
Dimension B
12½
14¾
14 7/ 8
213/8
25½
Dimension C
21
22
24½
27¾
28½
Dimension D
2¾
2½
2½
3½
2¾
Dimension E
NA
NA
NA
NA
29
Dimension F
171/16
18½
22
32¼
38¼
Dimension G
201/16
21½
25
35¼
41¼
Dimension H
1½
1
11/ 8
11/ 8
1
Crate Dimensions
(H x W x D
31x23x28
31x23x32
32x23x40
33x29x42
35x33x56
Shipping Weight
110
161
181
320
450
Air Intake
280
375
800
1050
2500
Electrical Requirements
Volts
115V
115V
208/230V
208/2300V
208/230V
Hertz
60Hz
60Hz
60Hz
60Hz
60Hz
Phase
1
1
1
1
3
NEMAL6-20P
NA
Unit Dimensions
Dimension A
Plug
1.
2.
3.
4.
5.
6.
7.
8.
NEMA5-15P
NEMA5-20P NEMAL6-15P
Dimension A is the height of the unit. The unit width and depth (dimensions B and C) are the case dimensions. Add
approximately 2 inches to include the plumbing connections.
Dimension D is the distance from the floor to the bottom of the unit case (height of the castors).
Dimension E is the distance from the floor to the center of the DRAIN connection (CFT-300 only).
Dimension F is the distance from the floor of the center of the OUTLET connection.
Dimension G is the distance from the floor of the center of the INLET connection.
Dimension H is the distance from the unit's left side to the center of the INLET, OUTLET and DRAIN connections.
Weights are given in pounds
Air intake is given in cubic feet per minute.
Rev 01/30/97
-7-
Pressure
Pump Capacity1
Bar
0.7
PSI
10
0.5
8
MD-30 (60 Hz)
0.4
6
0.3
4
0.1
2
Pressure
MD-30 (50 Hz)
Bar
PSI
4.0
60
3.4
50
2.7
40
2.0
30
1.3
20
0.7
10
1
2
3
3.8
7.5
11.3
Flow
4
5
GPM
15.1
19.0
LPM
A=PD-1 60Hz
B=PD-1 50Hz
C=PD-2 60Hz
D=PD-2 50Hz
C
A
D
B
1
2
3
4
GPM
3.8
7.5
11.3
15.1
LPM
Flow
1. To determine which pump is installed, refer to the
label on the rear of your unit.
-8-
Section III Installation
Site
The unit should be located in a laboratory or clean industrial environment
where ambient temperatures are inside the range of +13°C to +35°C.
Never place the unit in a location where excessive heat, moisture, or
corrosive materials are present.
The unit has an air-cooled refrigeration system. Air is drawn through the
front of the unit and discharged through rear and side panels. The unit must
be positioned so the intake and discharge are not impeded. A minimum
clearance of 18 inches (45 centimeters) on all vented sides is necessary for
adequate ventilation. Inadequate ventilation will cause a reduction in cooling
capacity and, in extreme cases, compressor failure.
Excessively dusty areas should be avoided and a periodic cleaning schedule
should be instituted (see Section V, Cleaning).
The unit will retain its full rated capacity in ambient temperatures up to
approximately +24°C. Above +24°C, derate the cooling capacity 1% for
every 0.5°C above +24°C, up to a maximum ambient temperature of +35°C.
Direction of Air Flow
-9-
Electrical
Requirements
The unit construction provides extra protection against the risk of
electrical shock by grounding appropriate metal parts. The extra
protection may not function unless the power cord is connected to a
properly grounded outlet. It is the user's responsibility to assure a
proper ground connection is provided.
Refer to Section II, Specifications, and to the serial number label on the rear
of the unit for the specific electrical requirements of your unit.
The CFT-300 is supplied with a disconnect box. Wire the power connections
in accordance to local, state and federal electrical codes. Double check all
wiring to make sure it is properly connected and protected from the elements.
The CFT-300 is also equipped with a compressor crankcase heater. The
crankcase heater warms the oil in the compressor and prevents refrigerant
from mixing with the oil. Before start up, the unit must be connected to its
power source for at least 12 hours. This allows time for the oil to be heated
and separate from the refrigerant.
Plumbing
Requirements
Before installing the unit to an instrument that previously used tap water as a
cooling fluid, flush the instrument several times to remove any rust or scale
that has built up. The manufacturer of the instrument should be able to
recommend a cleaning fluid for their equipment.
The plumbing connections are located on the rear of the unit and are labelled
OUTLET/SUPPLY and INLET/RETURN. CFT-25 to CFT-150 connections
are ½ inch FPT, CFT-150s with CP-55 pumps are ¾ inch and CFT-300
connections are ¾ inch FPT.
Remove the plastic protective plugs from both plumbing connections.
Connect the OUTLET/SUPPLY fitting to the inlet of the instrument being
cooled. Connect the INLET/RETURN fitting to the outlet of the instrument
being cooled.
Never connect the fittings to your building water supply or any water
pressure source.
Plumbing Connections
(Typical)
- 10 -
Two sets of plumbing adapters are included with CFT-25 to CFT-150 units.
One set of adapters will accept 3/8 inch ID tubing. The other set will accept
½ inch ID tubing. If the unit is being plumbed using flexible tubing, install
one set of adapters in the plumbing ports. To prevent leaking, be sure to
wrap the threads of the adapters with Teflon® sealing tape before installing
them in the plumbing ports.
Flexible tubing, if used, should be of heavy wall or reinforced construction.
All tubing should be rated to withstand 80 psig at +30°C. Make sure all
tubing connections are securely clamped. Avoid running tubing near radiators, hot water pipes, etc. If substantial lengths of tubing are necessary,
insulation may be required to prevent loss of cooling capacity.
Tubing and insulation are available from NESLAB. Contact our Sales
Department for more information (see Preface, After-sale Support).
It is important to keep the distance between the unit and the instrument
being cooled as short as possible, and to use the largest diameter tubing
practical. Tubing should be straight and without bends. If diameter
reductions must be made, they should be made at the inlet and outlet of the
instrument being cooled, not at the CFT.
If substantial lengths of cooling lines are required, they should be pre-filled
with cooling fluid before connecting them to the unit.
Fluids
The selected fluid must have a viscosity of 50 centistokes or less at the
lowest operating temperature.
Never use flammable or corrosive fluids with this unit. Distilled and
deionized water may be aggressive and cause material corrosion.
Please contact NESLAB before subjecting this unit to prolonged
exposure to distilled or deionized water.
Tap water is the recommended fluid for operation from +8°C to +30°C. See
Water Quality Standards and Recommendations on the next page.
Below +8°C, a non-freezing fluid must be used. A mixture of tap water and
laboratory grade ethylene glycol is suggested.
Do not use automobile anti-freeze. Commercial anti-freeze contains
silicates that can damage the pump seals. Use of automobile
anti-freeze will void the manufacturer’s warranty.
- 11 -
Water Quality Standards
and Recommendations
Permissible(PPM)
Microbiologicals
(algae,bacteria,fungi)
Desirable(PPM)
0
0
Calcium
<40
0.6
Chloride
250
<25
Copper
1.3
1.0
Iron
0.3
<0.1
Lead
0.015
0
Magnesium
<12
0.1
Manganese
0.05
<0.03
10 as N
0
Potassium
<20
0.3
Silicate
25
<1.0
Sodium
<20
0.3
Sulfate
250
<50
Hardness
17
<0.05
Total Dissolved Solids
50
10
6.5-8.5
7-8
0.01*
0.05-0.1*
Inorganic Chemicals
Nitrates\Nitrites
Other Parameters
pH
Resistivity
* Megohm-Cm (Compensated at 25C)
Unfavorably high total ionized solids (TIS) can accelerate the rate of galvanic corrosion. These contaminants can function as electrolytes which
increase the potential for galvanic cell corrosion and lead to localized
corrosion such as pitting which can be observed at the studs and on the
outside surface of cooling coils. Eventually, the pitting will become so
extensive that the coil will leak refrigerant into the water reservoir.
As an example, raw water in the United States averages 171 ppm (as NaCl).
The recommended level for use in a water system is between 0.5 to 5.0 ppm
(as NaCl).
Recommendation: Initially fill the tank with distilled/deionized water. Do not
use untreated tap water as the total ionized solids level may be too high.
- 12 -
Maintain this water quality at a resistivity of between 1 to 10 megohm-cm
(compensated at 25°C) by using a purification system. Although the initial fill
may be as high as 10 megohm-cm (compensated at 25°C), the desired level
for long time usage is 1 to 3 megohm-cm (compensated at 25°C).
The above two recommendations will reduce the electrolytic potential of the
water and prevent or reduce the galvanic corrosion observed.
18.30
Resistivity (megohm-cm @ 25°C)
Not Recommended, Increasingly Corrosive
15.00
10.00
Operations with Stainless Steel Systems
3.00
1.00
Operations with
Mixed Metals
Copper/Brass/
Stainless Steel
CONSULT MATERIALS ENGINEER
0.10
0.05
10
20
30
40
50
60
Temperature °C
Water Quality Considerations
- 13 -
70
80
Filling Requirements
Remove the reservoir access panel by unscrewing the thumbscrews. Locate
the reservoir plug (square nut). Remove the plug and fill the reservoir with
clean cooling fluid, following the special considerations outlined in the
following paragraphs.
Thumbscrew
Reservoir Access Panel
Reservoir Plug
Reservoir filling locations (Typical)
NOTE: The CFT-300 has a FILL lamp which illuminates whenever the
reservoir level is below normal operating level.
Circulating to a closed system (closed to the atmosphere)
Fill the reservoir to the bottom of the fill hole threads. Since the reservoir
capacity is small compared to many instruments being cooled, have extra
cooling fluid on hand to keep the system topped off when external circulation
is started.
NOTE: The tank in your unit has a vent which relieves pressure built up from
thermal expansion of water. The vent is located on the reservoir plug. It
activates when tank pressure reaches 3 - 5 psi.
Do not replace reservoir plug with an non-vented type or damage to
the tank may occur.
Circulating to an open system (open to the atmosphere)
Fill the reservoir so ¾ of the fill hole threads are covered. Wrap the tank
plug with Teflon® sealing tape. Replace the tank plug and tighten securely to
prevent air entry.
When circulating cooling fluid to an open vessel or tank, connect the OUTLET/SUPPLY and INLET/RETURN lines to the open tank. Secure the
INLET/RETURN (suction) line below the fluid surface. The INLET/RETURN
line should be submerged deep enough to avoid sucking air. Make sure the
INLET/RETURN line is free of particles and debris that can block the flow of
fluid. A baffle or screen may be required.
- 14 -
Section IV Operation
Start Up
Before starting the unit, double check all electrical and plumbing connections
and make sure the circulating system (the CFT, the instrument being cooled,
and the tubing that connects them) has been properly filled with cooling fluid.
To start the unit, place the POWER Switch to the on ( I ) position. The
refrigeration system and the recirculation pump will start. The POWER
Switch illuminates (except for the CFT-150) to indicate the system is operating. Units with PD pumps display the pump operating pressure on the
RECIRCULATING PRESSURE gauge.
To turn the unit off, place the POWER Switch to the off ( 0 ) position.
The Cool LED on the front panel indicate the status of the refrigeration
system. It illuminates to indicate the refrigeration system is removing heat
from the cooling fluid. As the operating temperature approaches the
temperature setpoint, the LED will extinguish.
The Idle LED on the front panel of CFT-150 units indicates the unit is in a
hot-gas-bypass mode of operation. As the operating temperature approaches
the temperature setpoint, the Cool and Idle LEDs cycle to indicate the
approximate duty cycle of the unit.
When the unit is shut off, wait approximately five minutes before restarting.
This allows time for the refrigeration pressures to equalize. If the pressures
are not allowed to equalize, the compressor will short-cycle (clicking sound)
and no cooling will occur.
Analog Temperature
Controller
Temperature Adjustment
To adjust the temperature setpoint, turn the calibrated °C dial on the front of
the unit to the desired temperature.
Analog Temperature Controller (Typical)
- 15 -
Digital Temperature
Controller
Temperature Adjustment
To display the temperature setpoint, press and hold the DISPLAY switch. To
adjust the temperature setpoint, press and hold the DISPLAY switch and turn
the ADJUST knob until the desired temperature setpoint is indicated on the
digital display. Once the setpoint is adjusted, release the DISPLAY switch.
The display will now indicate the temperature of the fluid in the reservoir.
NOTE: Inadvertent movement of the ADJUST knob, regardless of the
position of the DISPLAY switch, will result in a change in the setpoint. This
change will not be immediately reflected on the digital display, unless the
DISPLAY switch is pressed. The digital display will eventually change as the
unit reacts to the new setpoint.
Digital Temperature Controller (Typical)
Pressure Relief Valve
Units with PD pumps have a pressure relief valve which establishes the
maximum operating pressure of the unit. If the pressure of the fluid leaving
the pump exceeds the valve setting, the relief valve will bypass the fluid
within the unit to relieve the pressure. The relief valve does not determine
the actual operating pressure; the operating pressure is determined by the
back pressure of the system.
If an adjustment is necessary, contact our Customer Service Department.
- 16 -
High Temperature
Cutout (Optional)
The High Temperature Cutout (HTC) is designed to shut down the unit in the
event the temperature of the fluid in the reservoir exceeds the HTC setting.
The HTC is normally located on the rear of the unit.
NOTE: The HTC temperature scale is in °F.
CFT-300 High/Low
Pressure Cutout
CFT-300 units are equipped with high and low refrigeration pressure cutouts.
Should either cutout activate the unit will shut down.
The High Pressure Cutout (HPC) activates if there is a blockage in the
refrigeration lines or if the refrigerant temperature becomes too hot. The
HPC is factory preset at 400psi.
The Low Pressure Cutout (LPC) activates if there is a leak in the refrigeration lines. THE LPC is factory preset at 4psi.
Both cutouts are located inside the case behind the rear panel. Once the
cause of the shut down has been determined and corrected, manually
depress the white button on the applicable cutout. If a "click" is not heard
when depressing the button, the cutout was not activated and the unit shut
down for another reason.
CFT-150 High
Pressure Cutout
Some CFT-150 units are equipped with High Pressure Cutouts (HPC).
Should the HPC activate the unit will shut down.
The HPC activates if there is a blockage in the refrigeration lines or if the
refrigerant temperature becomes too hot. The HPC is factory preset at
400psi.
The cutout is located inside the case behind the rear panel. Once the cause
of the shut down has been determined and corrected, manually depress the
white button on the applicable cutout. If a "click" is not heard when depressing the button, the cutout was not activated and the unit shut down for
another reason.
- 17 -
Heater Package
(Optional)
Heaters are controlled by a switch on the temperature controller. The heater
itself is accessible through the small service panel on the rear of the unit.
These units also have a Low Level indicator. The indicator illuminates if the
fluid level in the reservoir drops below proper operating level.
Illustration A shows the desired fluid level for normal operation.
Should the reservoir be filled as shown in illustration B, units designed to
operate at high-end temperatures (near boiling) may cause air in the reservoir to become trapped. The air can be vented by slightly tilting the unit
forward on its front castors.
Any fluid venting from the reservoir will drain through a hose which feeds to
a small hole in the bottom of the unit.
Do not used silicon-based fluids with units designed to operate at high
temperatures. These type fluids will damage the hoses and pump seal.
Fluid Level
Fluid Level
Illustration A
Illustration B
- 18 -
External Pressure
Regulator (Optional)
For applications requiring a maximum pressure less than 55 PSI (380 kPa),
an External Pressure Reducer (EPR) is available. An EPR allows an adjustable operating pressure of 10 to 50 PSI (70 to 345 kPa). If the pressure of
the fluid leaving the chiller exceeds the relief valve setting, the relief valve
will bypass excess fluid back into the chiller to relieve the overpressure.
The pressure of the system is determined by the back pressure of the
connected equipment and the flow rate of the recirculating fluid to your
application. Connect the EPR as described.
NOTE: Install the fittings in the
exact sequence shown.
NOTE: Use Teflon ® tape on all
threaded fittings.
Connect the Inlet Tee Assembly
(1) to the chiller. Connect the
Outlet Tee Assembly (2) to the
chiller. Attach the relief valve (3)
to the Outlet Tee Assembly (2).
Attach the Hose Nipple (4) to the
Relief Valve (3). Attach the Hose
(5) between the Inlet Tee Assembly (1) and the Hose Nipple (4).
The EPR is now installed. Connect the inlet (to your application) to the
remaining fitting of the Outlet Tee Assembly (2). Connect the outlet (from
your application) to the remaining fitting of the Inlet Tee Assembly (1).
Tighten the hose clamps tight enough to prevent leakage. Do not overtighten
or the clamps will bite into the flexible tubing and cause excessive wear. If a
torque wrench is available, torque hose clamps to 50 in/lbs (280 cm/kg).
Nylon-reinforced hose tends to cold-flow, so the clamps will need to
retorqued later. (The hose clamps do not actually loosen, but rather the hose
outside diameter decreases!).
The "T" adjustment handle is equipped with a locknut. To adjust the relief
pressure setting loosen the locknut and turn the "T" handle to the minimum
pressure setting (direction of arrow).
To simulate blockage, close (or pinch off) the hose between the EPR outlet
tee assembly and the instrument being cooled. Monitor the operating pressure of the unit. Turn the "T" handle until the desired relief pressure is set.
(The EPR valve cannot be set lower than the total back pressure of the
instrument being cooled or the instrument will not receive any flow.)
Tighten the locknut to secure the position of the "T" handle. Open the hose
between the EPR outlet tee assembly and the instrument being cooled.
- 19 -
Section V Maintenance and Service
For personal safety and equipment reliability, the following procedure
should only be performed by a competent technician. Contact our
Service Department for assistance (see Preface, After-sale Support).
Service Contracts
NESLAB offers on-site Service Contracts that are designed to provide
extended life and minimal down-time for your unit. For more information,
contact our Service Department (see Preface, After-sale Support).
Draining the
Reservoir
The CFT-300 is equipped with a ½ inch FPT DRAIN fitting located on the
rear of the unit.
To drain the CFT-25 to CFT-150 reservoirs we recommend the use of a
wet/dry vacuum. Remove the reservoir plug and carefully insert the wet/dry
vacuum so as not to damage the cooling coils. NOTE: Tilting the unit more
than 45° may allow compressor oil to seep into the suction line.
Cleaning
Reservoir
Periodically inspect the fluid inside the reservoir. If cleaning is necessary,
flush the reservoir with a cleaning fluid compatible with the circulating
system and the cooling fluid.
The cooling fluid should be replaced periodically. When operating at low
temperatures, the concentration of water in the cooling fluid will increase
over time, leading to a loss of cooling capacity.
Before changing the cooling fluid, raise the operating temperature of the unit
to de-ice the cooling coils. Refer to Section III, Filling Requirements for
instructions on replacing the cooling fluid.
Condenser
For proper operation, the unit needs to pull substantial amounts of air
through a condenser. A build up of dust or debris on the fins of the condenser will lead to a loss of cooling capacity.
The lower front of the unit has a one-piece grille assembly. Gently pry the
assembly off with a flathead screwdriver. Use care not to scratch the paint.
Periodic vacuuming of the condenser fins is necessary. The frequency of
cleaning depends on the operating environment. We recommend a visual
inspection of the condenser be made monthly after initial installation. After
several months, the frequency of cleaning will be established.
- 20 -
Algae
To restrict the growth of algae in the reservoir, it is recommended that the
reservoir cover be kept in place and that all circulation lines be opaque. This
will eliminate the entrance of light which is required for the growth of most
common algae.
NESLAB recommends the use of Chloramine-T, one gram per gallon.
Pump Strainer
Units with PD pumps have a strainer. Refer to the pump label on the rear of
the unit to identify the type of pump in your unit.
If debris is in the system, the strainer will prevent the material from being
drawn into the pump and damaging the pump vanes.
After initial installation, the strainer may become clogged with debris and
scale. Therefore, the strainer must be cleaned after the first week of installation. After this first cleaning, a monthly visual inspection is recommended.
After several months, the frequency of cleaning will be established.
Before cleaning the strainer, disconnect the power cord from the power
source and drain the reservoir.
PD-1 pumps have a wire mesh strainer located in the pump head. PD-2
pumps have the strainer located in the pump suction line.
Remove the wrapper from the unit. Unscrew the larger of the two acorn nuts
on the pump head and remove the screen.
Clean the screen by rinsing it with water.
When the screen is clean, replace it in the strainer, tighten the acorn nut and
replace the wrapper. Refer to Section III, Filling Requirements for instructions on replacing the cooling fluid.
PD-2 Strainer
PD-1 Strainer
- 21 -
Pump Motor Lubrication
PD pump motors require periodic lubrication. Refer to the pump label on the
rear of the unit to identify the type of pump in your unit.
PD pumps use sleeve type bearings with large reservoirs. Oiling instructions
are generally posted on each motor. In the absence of instructions, add
approximately 30 to 35 drops of SAE 20 non-detergent oil to each bearing on
the following schedule (SAE 20 = 142 CS viscosity):
Duty Cycle
Oiling Frequency
Continuous
Once every year
Intermittent
Once every 2 years
Occasional
Once every 5 years
Fill Holes (Typical)
Hoses
The unit's internal and external hoses and clamps should be inspected and
tightened on at least a semiannual basis.
Suction Discharge Pressure
Speed Check
Unit
Pump Refrigerant Suction PSIG Discharge PSIG Speed °C/Min
CFT-25 PD-1
R134a
36 -38
160 - 170
4.8
CFT-25 MD-30
R134a
25 - 28
145 -160
4.0
CFT-33 PD1/2
R134a
42 - 45
180 - 200
3.0
CFT-75 PD1/2
R134a
37 - 41
170 -185
4.6
CFT-150 PD2
R22
70
270
2.8
CFT-300 PD2
R22
88 - 94
265 - 280
6.8
CFT-300 CP-55
R22
85 - 90
268 - 280
6.8
Standard temperature 60 Hertz units, derate 17% for 50 Hertz Units. +20°C fluid temperature, unit
in the COOL mode, +20°C ambient. 100% water in the reservoir. Wrapper removed.
- 22 -
Section VI Troubleshooting
Checklist
Unit will not start
Check the line cord, make sure it is plugged in.
Check the voltage of the power source. Make sure it is within the rated
voltage of the unit, ±10%.
Check that the Power Switch/Circuit Breaker has not tripped.
Check the setting on the optional High Temperature Cutout.
CFT-300 units are equipped with high and low pressure switches. If either
switch activates the unit will shut down. Once the cause has been determined you have to manually reset the switch. The switches are located
behind the rear panel. (See Section IV, Operation on page 17.)
Unit will not circulate fluid
Check the reservoir level. Fill, if necessary.
Make sure the pump has been purged.
Check the pressure gauge (units with PD pumps). If the reading is 60
psig, check the instrument being cooled for restrictions in the cooling line.
Check the pump strainer (units with PD pumps). A clogged strainer can
starve the pump.
Inadequate temperature control
If the temperature continues to rise, make sure the heat load of the
instrument being cooled does not exceed the rated specification. (See
Section II, Specifications on page 6.)
Make sure the air intake and discharge are not impeded and the ambient
temperature does not exceed +35°C.
Make sure the condenser is free of dust and debris. (See Section VI,
Cleaning on page 20.)
If the compressor short-cycles (a clicking sound), check the line voltage.
It should be within the 10% of the specified voltage. Wait 5 minutes
before restarting the unit.
Service Assistance
If, after following these troubleshooting steps, your unit fails to operate
properly, contact our Service Department for assistance (see Preface, Aftersale Support). Before calling, please refer to the serial number label on the
rear of the unit to obtain the following information:
- unit BOM number
- unit serial number
- voltage of unit
- voltage of power source
- 23 -
Pump Flow Diagram
Relief Valve
Reservoir
(PD Pumps Only)
Pressure Gauge
(PD Pumps Only)
Strainer (PD Pumps Only)
Pump
Supply
Return
WARRANTY
NESLAB Instruments, Inc. warrants for 12 months from date of shipment any NESLAB unit according to the
following terms.
Any part of the unit manufactured or supplied by NESLAB and found in the reasonable judgment of NESLAB
to be defective in material or workmanship will be repaired at an authorized NESLAB Repair Depot without
charge for parts or labor. The unit, including any defective part must be returned to an authorized NESLAB
Repair Depot within the warranty period. The expense of returning the unit to the authorized NESLAB Repair
Depot for warranty service will be paid for by the buyer. NESLAB’s responsibility in respect to warranty
claims is limited to performing the required repairs or replacements, and no claim of breach of warranty shall
be cause for cancellation or recision of the contract of sales of any unit.
With respect to units that qualify for field service repairs, NESLAB’s responsibility is limited to the component
parts necessary for the repair and the labor that is required on site to perform the repair. Any travel labor or
mileage charges are the financial responsibility of the buyer.
The buyer shall be responsible for any evaluation or warranty service call (including labor charges) if no
defects are found with the NESLAB product.
This warranty does not cover any unit that has been subject to misuse, neglect, or accident. This warranty
does not apply to any damage to the unit that is the result of improper installation or maintenance, or to any
unit that has been operated or maintained in any way contrary to the operating or maintenance instructions
specified in NESLAB’s Instruction and Operation Manual. This warranty does not cover any unit that has
been altered or modified so as to change its intended use.
In addition, this warranty does not extend to repairs made by the use of parts, accessories, or fluids which are
either incompatible with the unit or adversely affect its operation, performance, or durability.
NESLAB reserves the right to change or improve the design of any unit without assuming any obligation to
modify any unit previously manufactured.
THE FOREGOING EXPRESS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR
IMPLIED, INCLUDING BUT NOT LIMITED TO WARRANTIES OR MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE.
NESLAB’S OBLIGATION UNDER THIS WARRANTY IS STRICTLY AND EXCLUSIVELY LIMITED TO THE
REPAIR OR REPLACEMENT OF DEFECTIVE COMPONENT PARTS AND NESLAB DOES NOT ASSUME
OR AUTHORIZE ANYONE TO ASSUME FOR IT ANY OTHER OBLIGATION.
NESLAB ASSUMES NO RESPONSIBILITY FOR INCIDENTAL, CONSEQUENTIAL, OR OTHER DAMAGES INCLUDING, BUT NOT LIMITED TO LOSS OR DAMAGE TO PROPERTY, LOSS OF PROFITS OR
REVENUE, LOSS OF THE UNIT, LOSS OF TIME, OR INCONVENIENCE.
This warranty applies to units sold in the United States. Any units sold elsewhere are warranted by the affiliated
marketing company of NESLAB Instruments, Inc. This warranty and all matters arising pursuant to it shall be
governed by the law of the State of New Hampshire, United States. All legal actions brought in relation hereto
shall be filed in the appropriate state or federal courts in New Hampshire, unless waived by NESLAB.